1. Technical Field
The present disclosure relates to a method for making carbon nanotube slurry.
2. Description of Related Art
A field emission cathode is an important element for a field emission device. A field emission cathode is usually made by printing a cathode slurry including a plurality of electron emitters on a cathode conductive layer and exposing the electron emitters from the cathode slurry.
Carbon nanotubes (CNT) are very small tube-shaped structures, and have extremely high electrical conductivity, very diameters, and a tip-surface area near the theoretical limit. Thus, carbon nanotubes can transmit an extremely high electrical current and be used as the electron emitters to make the cathode slurry. A Length of carbon nanotubes affects the field emission characteristics of the carbon nanotube slurry. If lengths of carbon nanotubes are too long, the field emission characteristics of the carbon nanotube slurry will be decreased. In the conventional method, long carbon nanotubes are trimmed by a ball milling method. However, the shorten lengths of the carbon nanotubes via the ball milling are not uniform, and this leads to uneven field emission characteristic.
What is needed, therefore, is to provide a method for making the carbon nanotube slurry that can overcome the above-described shortcomings.